The present invention relates to a piezoelectric element including a piezoelectric layer which is interposed between electrode layers which form a pair, a liquid ejecting head which includes the piezoelectric layer, and a liquid ejecting apparatus.
A liquid ejecting apparatus is an apparatus which includes a liquid ejecting head, and ejects various types of liquid from the liquid ejecting head. As the liquid ejecting apparatus, for example, there is an image recording apparatus such as an ink jet printer, and an ink jet plotter; however, these days, the liquid ejecting head is also used in various manufacturing devices by taking advantage that it is possible to make a very small quantity of liquid land on a predetermined position accurately. For example, the liquid ejecting head is used in a display manufacturing device which manufactures a color filter of a liquid crystal display, or the like, an electrode forming device which forms an electrode of an organic electro luminescence (EL) display, a surface light emission display (FED), or the like, and a chip manufacturing device which manufactures a biochip (biochemical element). In addition, a recording head for an image recording device ejects liquid ink, and a coloring material ejecting head for a display manufacturing device ejects a solution of various colors of R (red), G (green), and B (blue). In addition, an electrode material ejecting head for an electrode forming device ejects a liquid electrode material, and a bio-organic material ejecting head for a chip manufacturing device ejects a solution of a bio-organic material.
The above described liquid ejecting head includes a piezoelectric element which causes a pressure change to liquid in a pressure chamber. The piezoelectric element is configured by stacking, for example, a lower electrode layer which functions as an individual electrode which is provided in each pressure chamber, a piezoelectric layer such as lead zirconate titanate (PZT), and a higher electrode layer which functions as a common electrode which is common to a plurality of the pressure chambers, respectively, in order from a side which is close to the pressure chamber, using a film formation technology. In addition, a portion of the piezoelectric layer which is interposed between the higher and lower electrode layers becomes an active unit which is deformed due to an application of a voltage to both the electrode layers. Here, when the piezoelectric layer is deformed, there is a concern that a stress may be concentrated at a border portion between the active unit and a portion which is not the active unit (non-active unit), and a crevice (crack), or the like, may occur in the piezoelectric layer which configures the piezoelectric element. For this reason, a technology in which a rigidity of the border position of the piezoelectric element is increased by extending the piezoelectric layer and the higher electrode layer to the outside of the pressure chamber in the longitudinal direction is disclosed (for example, refer to JP-A-2013-158909).
However, there is a concern that it may not be possible to sufficiently suppress a problem of the occurrence of a cracking, or the like, in the piezoelectric layer, even when the above described configuration is adopted.